UCV7, AN AVOCADO ROOTSTOCK TOLERANT TO SALINITY

Abstract

Avocado (Persea americana Mill.) is one of the 20 most important fruit crop worldwide. However, its growing areas are limited because some avocado varieties are very sensitive to salinity. Due to a rising salinity levels in water resources used in avocado irrigation, a study was conducted to evaluate the effect of different salinity level present in irrigation water on Hass trees grafted on UCV7 (new selection of West Indian clonal avocado rootstocks), along with other rootstocks currently used in Chile as Nabal (Guatemalan race and seedling) and clonal Duke 7 (Mexican race), through vegetative growth and roots indicators, as well as nutrimental indicators. One year old trees were established in containers, under temperature controlled greenhouse and were subjected to irrigation at three NaCl concentrations: 0.66 mM (control treatment), 6 mM and 12 mM. Rootstocks showed different strategies to overcome this stress. Duke 7 increased vegetative growth and also nutrient uptake, which led to greater leaf damage by Cl and Na. Both Nabal and UCV7 rootstocks did not translocate Na from root to leaf thus inducing tolerance to salinity. UCV7 showed the lowest leaf damage under high salinity level in irrigation water, an important advantage compared to Nabal.